---
layout: example.html
title: Raster Source
shortdesc: Demonstrates pixelwise operations with a raster source.
docs: >
  <p>
    This example uses a <code>ol/source/Raster</code> to generate data
    based on another source.  The raster source accepts any number of
    input sources (tile or image based) and runs a pipeline of
    operations on the input pixels.  The return from the final
    operation is used as the data for the output source.
  </p>
  <p>
    In this case, a single tiled source of imagery is used as input.
    For each pixel, the Vegetation Greenness Index
    (<a href="http://www.tandfonline.com/doi/abs/10.1080/10106040108542184#.Vb90ITBViko">VGI</a>)
    is calculated from the input pixels.  A second operation colors
    those pixels based on a threshold value (values above the
    threshold are green and those below are transparent).
  </p>
tags: "raster, pixel, maptiler"
resources:
  - https://unpkg.com/d3@4.12.0/build/d3.js
cloak:
  - key: get_your_own_D6rA4zTHduk6KOKTXzGB
    value: Get your own API key at https://www.maptiler.com/cloud/
---
<div class="rel">
  <div id="map" class="map"></div>
  <div id="plot"></div>
</div>
